Hi bhay,

The billing code calculation should be applied from the date you received the amended statement from E.ON. So (without seeing all the information) on first look I'd say the bill is dated 26/06/09 therefore E.ON can charge for consumption back to 26/06/08. Anything prior to 26/06/08 is cleared by E.ON.

What this means is, as you moved out in September 2008 the charges will end in September 2008. So the period E.ON are billing you for in this example in actually June 2008 to September 2008, you technically are paying for 3 or so months worth of energy.

What date did the account start bhay? An idea of the start date would give me a good idea of how much I'd expect you to be left to pay, £400 maybe to high.

Again bear in mind I'm talking without seeing all the figures and dates so I may be incorrect, but I hope this helps a little.

Brian